Question

In a paper chromatography experiment, a sample of a

pigment is separated into two components, X and Y, as
shown in the figure above. The surface of the paper is
moderately polar. What can be concluded about X and Y
based on the experimental results?
(A) X has a larger molar mass than Y does.
(B) Y has a larger molar mass than X does.
(C) X is more polar than Y.
(D) Y is more polar than X.

Answer 1

In a paper chromatography experiment, if one component travels farther than another, it indicates that the farther-traveling component is less polar. Thus, component X is more polar than component Y as it adheres more to the moderately polar paper.

Step-by-step explanation:

In paper chromatography, the separation of compounds is based on their relative affinities to the stationary phase (the paper) and the mobile phase (the solvent). Given that the paper is moderately polar, compounds that are more polar would tend to adhere more to the paper and therefore travel less distance from the baseline when compared to less polar compounds. In the scenario described, where a pigment is separated into components X and Y, if one travels farther on the paper than the other, it is likely due to differences in polarity rather than molar mass. Since Y has traveled farther, it is less polar than X, which indicates that X has a stronger interaction with the polar paper. Therefore, the correct conclusion is that X is more polar than Y. The information provided about charges or the ratios of carbon to hydrogen is not directly relevant to the question about polarity and the separation in chromatography. Thus, the other options are not supported by the details of the chromatography experiment.

Answer 2

In the given experiment, since X moved farther than Y, it can be concluded that X is less polar than Y. Therefore, the correct answer is (D).

Molecules that are more polar are attracted more strongly to the stationary phase and therefore move slower along the paper. This is because the polar molecules interact with the polar groups in the stationary phase through dipole-dipole interactions or hydrogen bonds. As a result, they are held back and their movement is restricted.

In paper chromatography, molecules with higher polarity are attracted more to the polar stationary phase (paper) and move slower, while less polar molecules are more attracted to the mobile phase (solvent) and move faster. Therefore, in the given experiment, since X moved farther than Y, it can be concluded that X is less polar than Y. Therefore, the correct answer is (D).